This disclosure relates generally to the field of downhole tools and operations, and more particularly to method and system for lining tubulars.
Oil and gas wells extend from the surface to one or more underground formations of rock containing oil and/or gas. The wellbore is typically cased to stabilize the sides of the well, to prevent pollution of fresh water reservoirs and to prevent fluids from zones other than the oil and gas producing zones from entering the well. Typically, the casing is cemented into the wellbore.
At the oil and gas production zones, the casing is perforated to allow oil, gas and/or by-products to enter the casing. Perforation is typically formed in the casings with shaped explosive charges or projectiles from a perforating gun. Fluids entering the casings through perforations are produced to the surface or otherwise processed. For example, water may be separated downhole and pumped into a disposal zone while oil and gas are produced to the surface.
After a production zone is depleted of oil and/or gas, perforations for the zone may be sealed to prevent water production into the casing from the depleted zone while production of oil and/or gas continues from other non-depleted zones. Perforations may be sealed using squeezed cement, straddle patch and chemical techniques. Straddle patch techniques typically use two packers at each end of a smaller section of tubing to straddle and pack-off perforations of the depleted zone. Chemical techniques typically squeeze chemical blends into the water producing perforations to seal-off the flow.